Smell

Question 1

Define the concept of smell adaptation

Answer 1

Smelling the same odorant each trial will decrease investigation time, until a new odorant (the test odorant) is presented, leading to a spike in investigation time

Question 2

True/False? there is a direct link between chemical composition and odor

Answer 2

False

Question 3

What is the purpose of turbinates in the nasal cavity?

Answer 3

increase turbulence, purify and humidify air passing through nose

Question 4

Define the structure of the olfactory bulb

Answer 4

Sits on top of the cribriform plate, bundle of Mitral/Tufted cells connected to glomeruli which diffuse into olfactory sensory neurons past the cribriform plate, projecting cillia into the mucus layer lining the epithelium

Question 5

What causes the change in membrane potential of olfactory neurons?

Answer 5

Non-ionic odorants binding to receptors (GPCR)

Question 6

How many different receptors do you have? What percentage of the genome encodes for these receptors?

Answer 6

~350, 4%

Question 7

What is the idea of population coding of odor? What is wrong with this idea?

Answer 7

Each molecule has its own set of features which triggers specific receptors (a population code), which is random for each molecule

HOWEVER, molecules with similar structures trigger roughly the same area, and the same molecule at different concentrations trigger different areas

Question 8

How is olfactory bulb activity sent to the brain?

Answer 8

(technically it already is the brain)

APs travel from olfactory bulb through olfactory tract, diffusing into amygdala, piriform cortex, and entorhinal cortex

Question 9

What is the possible function of the anterior piriform cortex?

Answer 9

Detecting some features of the molecule such as length

Question 10

What is the possible function of the posterior piriform cortex?

Answer 10

Quality of the odor (sweet vs citrus etc)